1. Priority Claim
This application claims the benefit of priority from European Patent Application No. 12450032, filed May 25, 2012, which is incorporated by reference.
2. Technical Field
The present application relates to an earphone with suppression of ambient noise.
3. Related Art
An earphone may generally be used to play back music, speech, or both, or to play back a useful signal. In addition, an earphone may be configured to prevent or reduce the interfering effect of ambient noise. For example, some earphones provide a microphone at a location of the earphone. The microphone may receive interfering noise and, via a corresponding electronic circuit, transmit signals to generate phase-shifted counter-pulses on the loudspeaker of the earphone so that the interfering noises are suppressed in the ear.
In some earphones, a time delay of the sound between the microphone and loudspeaker may decrease the quality of noise suppression and the stability connected with the corresponding earphone structure. In these earphones a howling (resonance catastrophe) may result, thereby creating undesired positive feedback.